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author | Paul B Mahol <onemda@gmail.com> | 2019-10-03 18:09:59 +0200 |
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committer | Paul B Mahol <onemda@gmail.com> | 2019-10-06 15:09:38 +0200 |
commit | e37edc70bd884182021035f6754464b904cfbf9b (patch) | |
tree | 89821bf860206792c01ff03a98d4ca474fcb4d26 /doc/filters.texi | |
parent | a27c0781ddede0176063c43ec97ea4152ef4c8bc (diff) | |
download | ffmpeg-e37edc70bd884182021035f6754464b904cfbf9b.tar.gz |
avfilter: add anlms filter
Diffstat (limited to 'doc/filters.texi')
-rw-r--r-- | doc/filters.texi | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index fbc3a404dd..468227ce50 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -1814,6 +1814,58 @@ Change output mode. Syntax for the command is : "i", "o" or "n" string. @end table +@section anlms +Apply Normalized Least-Mean-Squares algorithm to the first audio stream using the second audio stream. + +This adaptive filter is used to mimic a desired filter by finding the filter coefficients that +relate to producing the least mean square of the error signal (difference between the desired, +2nd input audio stream and the actual signal, the 1st input audio stream). + +A description of the accepted options follows. + +@table @option +@item order +Set filter order. + +@item mu +Set filter mu. + +@item eps +Set the filter eps. + +@item leakage +Set the filter leakage. + +@item out_mode +It accepts the following values: +@table @option +@item i +Pass the 1st input. + +@item d +Pass the 2nd input. + +@item o +Pass filtered samples. + +@item n +Pass difference between desired and filtered samples. + +Default value is @var{o}. +@end table +@end table + +@subsection Examples + +@itemize +@item +One of many usages of this filter is noise reduction, input audio is filtered +with same samples that are delayed by fixed ammount, one such example for stereo audio is: +@example +asplit[a][b],[a]adelay=32S|32S[a],[b][a]anlms=order=128:leakage=0.0005:mu=.5:out_mode=o +@end example +@end itemize + @section anull Pass the audio source unchanged to the output. |